A barcode is an optical machine-readable representation of information. Devices for identifying or extracting information from barcodes are often referred to as barcode readers or barcode reading devices. Image-based barcode readers operate by capturing and decoding images of barcodes. In typical operation, one or more light sources are activated to illuminate a region of space that includes a barcode. Light is reflected from the barcode toward the barcode reader. One or more lenses within the barcode reader focus an image of the barcode onto an image sensor, which is a two-dimensional array of photosensors (i.e., detectors that are sensitive to electromagnetic radiation). The photosensors are read electronically to provide a two-dimensional array of image data corresponding to the barcode. A decoder then processes the image data and extracts the information contained in the barcode.
Some barcode readers are capable of operating in either a “hand-held mode” or a “presentation mode.” When a barcode reader is operating in hand-held mode, a user holds the reader in his/her hand, manually positions the reader so that a barcode is located within the reader's field of view, and activates a trigger located on the reader. The barcode is read in response to activation of the trigger. In contrast, when a barcode reader is operating in presentation mode, an item bearing a barcode is presented to the reader rather than the reader being presented to the barcode. In presentation mode, barcodes are read automatically when they are detected within the reader's field of view. When a reader is operating in presentation mode, it is typically desirable for the reader to be held in a fixed position without the user having to hold the reader in place. A stand may be utilized for this purpose.
Mobile devices (e.g., smartphones, tablet computers) are in widespread use today, most often in connection with entertainment, communications and office productivity. Many mobile devices include a camera, and applications have been developed for using the camera to read barcodes.